Fluid pressure intensifying system

Abstract

A fluid pressure-intensifying system of the double-acting type has a recompression valve assembly that meters working fluid of the low pressure hydraulic cylinder to control low pressure piston travel upon reversal at the end of each pressure-intensifying stroke.

I claim: 
     
       1. A recompression valve for regulating working fluid flow into and out of a hydraulic working fluid cylinder comprising a valve assembly having a valve body with a first passage in fluid communication with said control valve and a second passage in fluid communication with said one side of said low pressure chamber, and a metering cylinder having an interior defining a metering chamber in fluid communication with both first; and second passages, said metering cylinder having a plurality or apertures in its cylindrical wall providing fluid communication between said metering chamber and said first passage: an inlet element means within said valve body in fluid communication with and between said first and second passages responsive to working fluid pressure to permit working fluid to either (a) flow from said control valve to said low pressure chamber when working fluid is directed to pressurize said one side of said low pressure chamber, or (b) flow from said low pressure chamber to an outlet element when working fluid is vented from said one side of said low pressure chamber;   an outlet element means located in said metering chamber between said inlet element means and said first passage responsive to working fluid pressure and so arranged as to normally seal said apertures from fluid communication with said metering chamber but in response to working fluid pressure will shift to expose the metering cylinder apertures to vent working fluid to permit working fluid to flow from said second passage to said first passage solely through said metering chamber when venting said one side of said low pressure chamber; and   a metering element means located in said metering chamber and so arranged as to control the position of said outlet element means in response to reduced working fluid pressure in said first passage whereby said flow through said metering chamber to said first passage occurs at a progressively greater rate as working fluid is initially vented from said one side of said working chamber.   
     
     
       2. The recompression valve means of claim 1 wherein said valve assembly comprises: a valve body within which said inlet element means, outlet element means, and said metering element means are axially aligned; and wherein said valve assembly includes an orifice plate separating said metering cylinder from said inlet element means and being provided with orifice passage therein in fluid communication with said first passage, said inlet element means being normally seated against said orifice plate to seal said orifice passages from fluid communication with said second passage, and said inlet element means and said orifice plate being provided with axially-aligned center passages providing fluid communication between said second passage and said outlet element whereby, when said inlet element means is sealed against said orifice plate and working fluid begins to vent from said low pressure chamber, working fluid pressure will shift said outlet element means to expose the metering cylinder apertures to venting working fluid at a rate determined by said metering element means. 
     
     
       3. The recompression valve of claim 2 wherein said valve assembly comprises an orifice plate separating said metering cylinder from said inlet element means having orifice passage therein in fluid communication with said first passage, said inlet element means being normally seated against said orifice plate to seal said orifice passages from fluid communication with said second passage, and said inlet element means and said orifice plate being provided with axially-aligned center passages providing fluid communication between said second passage and said outlet element means whereby, when said inlet element means is sealed against said orifice plate venting working fluid will pass through the aligned center passages into said metering cylinder and out through said metering cylinder apertures. 
     
     
       4. In a fluid pressure intensifying system comprising a source for supplying low pressure working fluid to a low pressure working fluid chamber; a control valve for directing working fluid to and from alternate sides of a low pressure reciprocating piston in said low pressure chamber; and a double-acting fluid pressure intensifier having a low pressure working fluid chamber and two high pressure fluid chambers, a low pressure reciprocating piston in said working fluid chamber and a high pressure reciprocating piston in each high pressure fluid chamber, the low and high pressure pistons being so arranged that low pressure fluid acting alternately on one side and then the other side of said low pressure piston will cause first one high pressure piston and then the other to compress fluid to a high pressure in its chamber and cause the other high pressure piston to evacuate its chamber to permit fluid to enter therein for pressurization on the next stroke; the improvement comprising: recompression valve means in fluid communication with said control valve and one side of said low pressure chamber which comprises inlet valve means for direction working fluid under pressure from said control valve into said low pressure chamber to act on one side of said low pressure piston to cause a high pressure piston to compress the fluid in its high pressure chamber to a high pressure; outlet valve means for venting working fluid from said one side of said low pressure chamber to said control valve including metering means for regulating the venting of working fluid through said outlet valve means so as to control the reduction of working fluid pressure when working fluid is vented from said low pressure chamber at the beginning of a piston stroke whereby a pressure spike-causing sudden movement of said low pressure piston on its reversal is avoided, said recompression valve means comprising   a valve assembly having a valve body with a first passage in fluid communication with said control valve and a second passage in fluid communication with said one side of said low pressure chamber, and a metering cylinder having an interior defining a metering chamber in fluid communication with both first and second passages, said metering cylinder having a plurality of aperture in its cylindrical wall providing fluid communication between said metering chamber and said first passage;   an inlet element means within said valve body in fluid communication with and between said first and second passages responsive to working fluid pressure to permit working fluid to either (a) flow from said control valve to said low pressure chamber when working fluid is directed to pressurize said one side of said low pressure chamber, or (b) flow from said low pressure chamber to an outlet element when working fluid is vented from said one side of said low pressure chamber;   an outlet element means located in said metering chamber between said inlet element means and said first passage responsive to working fluid pressure and so arranged as to normally seal said apertures from fluid communication with said metering chamber but in response to working fluid pressure will shift to expose the metering cylinder apertures to vent working fluid to permit working fluid to flow from said second passage to said first passage solely through said metering chamber when venting said one side of said low pressure chamber; and   a metering element means located in said metering chamber and so arranged as to control the position of said outlet element means in response to reduced working fluid pressure in said first passage whereby said flow through said metering chamber to said first passage occurs at a progressively greater rate as working fluid is initially vented from said one side of said working chamber.   
     
     
       5. The recompression valve means of claim 4 wherein said inlet element means, outlet element means, and said metering element means are axially aligned; and wherein said valve assembly includes an orifice plate separating said metering cylinder from said inlet element means and being provided with orifice passages therein in fluid communication with said first passage, said inlet element means being normally seated against said orifice plate to seal said orifice passages from fluid communication with said second passage, and said inlet element means and said orifice plate being provided with axially-aligned center passages providing fluid communication between said second passage and aid outlet element whereby, when said inlet element means is sealed against said orifice plate and working fluid begins to vent from said low pressure chamber, working fluid pressure will shift said outlet element means to expose the metering cylinder apertures to venting working fluid at a rate determined by said metering element means. 
     
     
       6. The recompression valve of claim 4 wherein said valve assembly comprises an orifice plate separating said metering cylinder from said inlet element means having orifice passages therein in fluid communication with said first passage, said inlet element means being normally seated against said orifice plate to seal said orifice passages from fluid communication with said second passage, and said inlet element means and said orifice plate being provided with axially-aligned center passages providing fluid communication between said second passage and said outlet element means whereby, when said inlet element means is sealed against said orifice plate venting working fluid will pass through the aligned center passages into said metering cylinder and out through said metering cylinder apertures. 
     
     
       7. The recompression valve means of claim 4 comprising a pair of said valve assemblies so arranged that when one assembly is directing working fluid to one side of said low pressure chamber the other assembly is directing working fluid from the other side of said low pressure chamber.   
     
     
       8. The recompression valve means of claim 7 wherein each valve assembly inlet element means, outlet element means, and said metering element means are axially aligned; and wherein each said valve assembly includes an orifice plate separating said metering cylinder from said inlet element means and being provided with orifice passages therein in fluid communication with said first passage, said inlet element means being normally seated against said orifice plate to seal said orifice passages from fluid communication with said second passage, and said inlet element means and said orifice plate being provided with axially-aligned center passages providing fluid communication between said second passage and said outlet element whereby, when said inlet element means is sealed against said orifice plate and working fluid begins to vent from said low pressure chamber, working fluid pressure will shift said outlet element means to expose the metering cylinder apertures to venting working fluid at a rate determined by said metering element means. 
     
     
       9. The recompression valve of claim 7 wherein each said valve assembly comprises an orifice plate separating said metering cylinder from said inlet element means having orifice passages therein in fluid communication with said first passage, said inlet elements means being normally seated against said orifice plate to seal said orifice passage from fluid communication with said second passage, and said inlet element means and said orifice plate being provided with axially-aligned center passages providing fluid communication between said second passage and said outlet element means whereby, when said inlet element means is sealed against said orifice plate venting working fluid will pass through the aligned center passages into said metering cylinder and out through said metering cylinder apertures.